Ruston Corporation applies manufacturing overhead to products on the basis of standard machinehours. Budgeted and actual overhead costs for the most recent month appear below: Original Actual Budget Costs Variable overhead costs: Supplies ........................................................... $ 9,000 $ 9,250 Indirect labor ................................................... 26 550 27,980 Total variable manufacturing overhead cost ...... 35 550 37 230 25. The original budget was based on 4,500 machinehours. The company actually worked 4,590 machine hours during the month and the standard hours allowed for the actual output were 4,700 machinehours. What was the total variable overhead efficiency variance for the month? A. $50 unfavorable B. $869 favorable C. $969 unfavorable D. $100 unfavorable